Manual toothbrushes are constructed as disposable articles. Latest after three month of use a manual toothbrush shall be replaced at least due to hygienic reasons. That means that consumer generally only expect a low pricing for manual toothbrushes. On the other hand, manual toothbrushes have to meet a lot of requirements, such as complex bristle fields in order to clean properly interdentally, the gum line as well as the back molar teeth. Further, a manual toothbrush has to be smooth to the gum and comfortable to handle. Thus, there is a continuous need for the manufacturer of manual toothbrushes to optimize production processes in order to work very cost effective. One problem of the manufacturing of manual toothbrushes is the production time. Speed reducing steps are the cooling times needed if injection molding is used and the complexity of the bristle fields. The latter requires a lot of successive steps, if anchor technology is used to fasten the bristle filaments to the brush head. In contrast, anchor-free bristling technologies further improve the complexity of the molding procedure which as a consequence increases the molding time.
Two different solutions to this problem have been offered mainly over the last years. The most pragmatic one is to offer low price and high price products wherein in low price products complexity of the whole brush, in particular the bristle field is reduced. However, usually the low price products show a worse cleaning.
Alternatively, it was disclosed to adapt the reuse system of electric toothbrushes which comprises a reusable handle and a disposable replacement brush head to the field of manual toothbrushes. Due to differences between manual and electric toothbrushes a direct adaptation of the system does not make any sense. For example, replacement brush heads of electric toothbrushes comprise the receiving cavity in the replacement brush head and the coupling element at the electric handle. However, the receiving element requires a large diameter of the neck portion. In addition, due to stability reasons the neck portions of replacement brush heads are made from very hard plastic material to impart a high rigidity and strength to the replacement brush head during use. This approach is impractical for manual brushes as the neck portion of manual brushes needs to be small and at least partially flexible for a comfortable and proper cleaning and handling.
EP1284618B1 shows manual toothbrushes comprising a replacement brush head wherein the coupling element is provided by the brush head and the receiving element is provided by the handle. Said manual toothbrush is reversible dividable between the neck and the handle and can be remounted by a snap-fit connection. The snap and fit connection comprises flexible working portions and locating elements which engage into a receiving portion comprising a deformable elastic mass. However, these kind of snap-fit connections are difficult to produce and may wear out over time.
In addition, the split in dividable manual toothbrush may cause additional problems regarding hygienic use. Rests of paste, saliva and/or bacteria may enter the split or may stick to any edge, if the dividable portion is not sealed completely. EP0602611B1 offers another dividable manual brush comprising a swivel joint which is sealed by a pressure elastic material at the split portion. However, an elastic sealing of the split increases the complexity of the manufacturing process thereby increasing the production costs.
It seems that providing replaceable brush head for manual toothbrushes does not solve the initially discussed problem, but provides an alternative high price and complex product. Thus, there is still a need of providing high quality manual toothbrushes showing a high degree of complexity, quality and variability being produced by low costs.